Tip for consumers: Don't.
Tip for consumers: Compare with vendors who sell rings set with diamonds or other jewels. Also note that rare earths are a rare resource mined using often environmentally and ecologically unfriendly techniques in a manner that violates human resources. Ask if the rare earths in these rings were mined/extracted in a responsible, ethical, mindful manner.
Tip for consumers: It's all ages for boys and girls (honestly though, I think teenage girls would love it! I know I do!)
Tip for consumers: While one can't be sure, the positive reviews or number of them may be deceiving because, from what it looks like (on Google Reviews), he seems to get people that he knows to give his site positive rating/reviews (if he's not doing that himself).
On the application process, other than what's said in the main part of the review, be advised that the site/application doesn't seem to have a minimum age, so there's no gaurantee that the models of this agency aren't underage.